Atomic structure, artwork

Caption: Computer artwork of the structure of an atom. An atom consists of one or more electrons (blue) which are orbiting in a shell about the tiny, central nucleus. The nucleus consists of protons (red) & neutrons (green). The number of electrically positive protons balance the number of electrically negative electrons to make the atom neutral overall. Each proton & neutron consists of 3 quarks, bound together by the strong nuclear force.